Mcabtz



Patented lli/lar. 27, i923. I

UNITE@ S'llivlhfi 1,449,664 narrar OFFICE.

MAX FRIZ, OF MLBERTSHOFEN, NEAR llrUNICl-, GERMANY, ASSIGNOR TBAYERISCHE MOTOREN WERKE AKTIENGESELLSCHAFT, OF '.MUNICH, GER- MANY.

MULTPLE-J'ET CARBURETOR.

Application led September 3, 1920. Serial No. 408,087.v

(GRANTED 'UNDER THE ERVISIONS 0F THE ACT 0F MARCH 3, 1921, 41 SiTAT. L.,1313.)

To all 107mm t may concern:

Be it lrnown that l, MAX Fnrz, a citizen of the German Republic, and aresident of Milbertshofen, near Munich, Bavaria, Germany,

have invented a new and useful Multiple- Jet Carburetor, for which lhave filed application for patent in Germany J une 9,

p 1917, and of which the following is a specilication.

This invention relates to a carburetor for use in such high altitudemotors as have, in comparison with their normally designedunder-structures an eX zessively large cylinder volume swept by thepiston and excessively small compression spaces, or one of thesefeatures, and in which it is of great impor-l tance that they receive atevery moment eX- actly that mixture (weight of charge) which theyrequire in View of the density of the air at each particular altitude.

The invention, therefore, has for its main object a carburetor, by meansof which the correct mixture can be admitted to the aforesaid type ofmotor at every flying elevation up to that particular altitude for whichthe motor hasebeen constructed.

Another object consists in the provision of means affording a powerreserve which the pilot may use in order to overcome greaterresistances, at low altitudes, for example when starting, by temporarilyincreasing the weight of charge admitted to the cylinders and therebyaugmenting the output of the engine.

A further object of the invention is to provide a carburetor which shallbe reliable in itspaction and very economical in the consumption of fuelby always giving the most favorable opening at every particular flyingelevation.

In carrying out the invention a multichamber carburetor is used, inwhich, according to the invention, two sets of throttle valves areprovided, of which one is intended to be actuated at the lowerelevations and the other according to altitude, the arrangement beingsuch, that one of the carburetor chambers is only intended for use atlow elevations and is just sufficiently large to supply the correctmixture at these elevations. rlhe other chambers have throttle valveswhich are operated together with that of the first-named chamber., andadditional throttle valves which are actuated according to altitude,automatically or by hand, and they are only opened after such height hasbeen reached in which the pressure of the atmosphere has alreadyconsiderably diminished.

The invention will best be understood by reference to the accompanyingdrawings which illustrate by way of example one form of carburetor withthree distinct carburetor chambers, each having its own fuel and airnozzles and its own throttle valve or valves respectively.

Fig. 1 is a longitudinal section through the carburetor.v

Fig. 2 a vertical cross section through the central chamber, and

Fig. 3 a horizontal cross section through Fig. l

Fig. t is a sectional view similar to Fig. l, illustrating theapplication of the augmenting device of the carburetor.

Fig. 5 is a horizontal cross section through the carburetor shown inFig. Ll.

Fig. 6 is a largely diagrammatic view, partly in section, of theautomatic altitude control.

Fig. 6a is a detail sectional view of the saine.

Fig. 7 illustrates the augmenting device and is a longitudinal sectionthrough same.

As will be seen from these figures the car-- buretor is subdivided intothree chambers, the central chamber being denoted by l and the two sidechambers by ll and Hl respectively. Chamber l is that section of thecarburetor which is not influenced by the varying atmospheric pressureas it is only provided with a manually controlled throttle valve c.Chambers ll and lll represent those sections in which the throttlevalves f3 and are controlled according to the varying air pressure. Saidcontrol is preferably carried out automatically ay some barometricdevice, but it may be effected by hand, means being provided,independently to adjust the throttles by hand a small amount in excessof the position inparted to them by the saidbarometric device. Thechambers ll and Hl are further provided with throttle valves c, (lcapable of being-operated by hand together with the valve a in chamber lby means of the control rod f. @n the latter being shifted'to the left,the throttle valve a will open first until it is about half open, duringwhich time the slotted link in connection with the valves ineffectivelypasses, owing to the slots, the throttle levers of the valves e and cZ.These throttle levers eventually come into contact with the respectiveend of the slots and the valves e and Z begin to open. Since the leverof throttle valve a has double the length of the throttle levers for thevalves e and eZ, the latter will open twice as quickly and be fully openwhen the throttle valve a has passed through the second half of itsmovement. The throttles a, c and Z therefore will be fully open all atthe same time'. Zhen closing the valves, the same proceedings take placein the reversed way; all three throttle valves starting to movesimultaneously and the valves e and Z) being already closed by theaction of their springs Zz, when the valve L is still half open. ln thisposition of the carburetor the chamber I is the only one to supplymixture until fully closed.

'l he throttle valves Z) and c only begin to open after an altitude hasbeen attained, 1n which theatmospheric pressure has already considerablydiminished. rlhey are entirely closed at ground level and in order tomaintain. as far as possible, the mean pressure of the lengine constantduring the ascent and according to the respective flying altitude, theyare gradually opened by displacement of the rod g towards the rightuntil, at the ultimate flying altitude, for which the motor has beenconstructed, they are fully open. The operation of these throttle valvesb and c will be the same whether they are controlled automatically bythe barometric device or by hand, as even in the latter case the pilotmust not begin to actuate these throttles before he has attained analtitude of considerably low atmospheric pressure.

.lf or the purpose of automatic control the rod g is extended and passesloosely' through a hole drilled in a bolt 7e which is swiveled in thefree end of the barometer controlled lever Z. At its extreme end saidrod r/ carries a fixed spring plate m, whilst a second spring` plate n.is slidable between the head of lever Z and the said spring plate m andis pressed against the lever by means of a compression spring 0 arrangedbetween the two spring plates. The amount which the spring` plates mayapproach each other is limited by the distance marked in llig. 7. rThepurpose of this arrangement will be described at a. later stage. Lever Zis supported with its lower end on a. shaft g1 which is adapted toslide, but not to rotate, in a bracket 7a and is in connection with ananeroid barometer or the like r, by the aspirations of which it is movedto and fro within the said bracket. The said aneroid barometer forms nopart of the invention and is therefore shown only diagrammatic in l andG of the drawings. rfhat portion of the shaft g upon which the lever Zis mounted is provided with a spiral groove into whch the boss of thelever fits with a key. lt will be seen, thus, that any displacement ofthe shaft g by the barometer will cause the lever to divert towards oraway from the carburetor. When the lever Z turns in the direction of thearrow t in Fig. -lit presses against a collar u upon the rod g causingsaine to move to the right and to open the throttles Z) and c, whereasmovement of the lever Z in the reverse direction will rause the saidthrottles to be closed.

The varous controlling operations are effected in the following manner:When the aeroplane starts to ascend the pilot opens the throttle a bymeans of the rod f. After this throttle Z has opened half its amount,the throttles e and (Z begin to open and they are fully open the momentthe throttle ct reaches its full open position. This, however bringsonly the carburetor chamber l into operation, since the chambers ll andlll are still closed by the throttle valves Z) and c. lVith thiscarburetor opening the motor will give its normal output at groundlevel. lVhen the aeroplane now continues to ascend, this output woulddecrease with the diminishing pressure of the atmosphere and to avoidthis, the throttle valves t and c are now opened automatically by theair pressure, or by hand as said before, by a corresponding movement ofrod f/. rlhe passages given free by these throttles 7) and c are atevery flying elevation of the aeroplane such, that the motor wouldalways maintain its normal performance up to that height for which ithas been constructed and in which altitude the throttles and c would befully open and would remain so as long as the aeroplane would be flyingat that or a higher elevation. lf now the enfrine is to be throttled orstopped, the throttles Z) and c would remain open. whereas the throttlesa, Z and e would be closed by hand by shifting the rod f towards theright. The throttles Z and e will be closed already after the rod f hasmoved through half its distance and the carburetor chamber l will be theonly one to continue in operation until. at last, the throttle valve o,has been closed. To again increase the engine performance the throttlea. only is i'irst opened and after it has moved through half its amount,the throttles e and (.Z are likewise caused to open in the manneralready described.

@n the aeroplane descending` into lower elevations the throttles 7) andc are closed according to the altitudes passed without any regard to theposition of the throttles 0 f? and e until, at ground level, boththrottles 7i and c are again fully closed. The no load or idlingarrangement which is usual in connection with most carburetors may beused in the ordinary way. 1t is shown in Fig 2 in which it is referredto as carburetor chamber lV.

In order to permit the chambers ll and III to commence Work already atground level, small slits z' may be made in the throttles b and cthrough Which, with the throttles d and e partly or fully open but thethrottles b and c still closed, a small amount of mixture would beadmitted, sutlicient just to ensure of the jets in the chambers ll andlll Working properly When the corresponding throttles d, e begin toopen.

To increase for a short time, as for example When starting, the outputof the en gine and to cause the same to deliver all that power which itis in position to deliver in view ot its large cylinders, the springplate m which is ixed at the extreme end of rod g may be depressed byhand against the resistance of the barometrie device through thedistance marked m in Fig. 7. Hereby the throttle valves o and c areopened a certain amount beyond the position imparted to them by 'thesaid baromet ric device and temporarily to admit an increased Weight otcharge into the cylindersJ What I claim is l. A multiple jet carburetorfor use in high altitude motors having excessively large cylinders andexcessively small com.- pression spaces in comparison with theunder-structure of the motor, said carburetor being subdivided into tivogroups or" selicontained curburetoi.' chambers, one group having asingle set of throttles and the other group having a duplicate set ofthrottles, each set being independent of the other.

2. A multiple jet carburetor for use in high altitude motors havingexcessively large cylinders and excessively small coinpression spaces incomparison with the under-structure of the motor, said carburetorcomprising one self-contained carburetor chamber having only onethrottling organ, and a number of likewise self-contained chambershaving a duplicate set of throti tling organs, each set beingindependent ot the other.

3. A multiple jet carburetor for use in high altitude motors havingexcessively large cylinders and excessively small compression spaces incomparison with the under-structure of the motor, said carburetorcomprising tvvo groups of self-contained carburetor chambers, one set otthrottling organs common to both groups and actuated in unison at loivaltitudes and a second set ot throttling organs for only one group to beactuated at high altitudes.

el. A multiple jet carburetor for use in high altitude motors havingexcessively large cylinders and excessively small compression spaces incomparison with the under-structure of the motor, said carburetorcon'iprising two groups ot self-contained carn buretor chambers, one setci' throttling organs common to both groups and actuated in unison atlow altitudes, a second set of throttling organs for only one group tobe actuated at high altitudes and having small by-pass openings throughwhich to supply a moderate amount of mixture when the said throttles areclosed and the first named set opened.

5. A multiple jet carburetor for use in high altitude ymotors havingexcessively large cylinders and excessively small compression spaces incomparison with the understructure oit the motor, said carburetorcomprising two groups of self-contained carburetor chambers, a handoperated set o'i throttles common to both groups to be actu ated at lowaltitudes, an additional set ot throttles for only one group to beactuated at high altitudes, a barometric device to automatically actuatesaid additional set ot throttles in accordance with the varying pressureof the atmosphere.

6. A multiple jet carburetor for use in high altitude motors havingexcessively large cylinders and excessively small compression spaoes incomparison with the under-structure ot the motor, said carburetorcomprising one group oit carburetor chambers to supply the correctmixture at low altitudes and another group to supply correct mixture athigh altitudes, a set or" throttling organs common to both groups, anadditional set of throttling organs for only one group, hand controlledmeans to actuate the low altitude throttles so that the throttles in thefirst named group ot carburetor chambers open in advance ot' thethrottles in the second named groups.

7. A multiple jet carburetor for use in high altitude motors havingexcessively large cylinders and excessively small com.- pression spacesin comparison With the under-structure of the motor, said carburetorcomprising a self-contained carburetor chamber to supply the correctmixture at low altitudes, a number of likewise selfcontained carburetorchambers to supply correct mixture at high altitudes, a set ofthrottling organs common to all chambers, an additional set otthrottling organs Within the high-altitude chambers to be actuated inunison, a hand operated control rod to actuate the lovv altitudethrottling organs, a lever in connection With said control rod to movethe throttling organ in the lovv altitude chamber, a slotted linkconnecting the loiv altitude throttles in the high altitude chamberswith that in the low altitude chambers, throttle levers in operativeconnecton with said slotted link and of a shorter length than the irstnamed throttle lever and acted upon by springs tending to keep thethrottle organs in their closed position.

8. A multiple jet carburetor tor use in high altitude motors havingexcessively large cylinders and excessively small compression spaces incomparison with the under-structure of the motor, said carburetorcomprising two groups of self-contained carburetor chambers, a. handoperated set ot throttles common to both groups to be actuated at lowaltitudes, an additional set of throttles for only one group to beactuated at high altitudes, a barometric device to automatically actuatesaid additional set of throttles in accordance with the varying pressureof the atmosphere, and means tern porarily to open the high altitudethrottles by hand against the resistance of the barometric device.

9. A multiple `iet carburetor for use in high altitude motors havingexcessively large cylinders and excessively small coinpression spaces incomparison with the under-structure of theniotor, said carburetorcomprising two groups of self-contained carburetor chambers7 a handoperated set of throttles common to both groups to be actuated at lowaltitudes, an additional set of throttles for only one group to beactuated at high altitudes, a. ba'rometric device to automaticallyactuate said additional set of throttles in accordance with the varyingpressure of the atmosphere, a lever adapted to be oseillated-by theaspirations of the baromet-ric device, a control rod to actuate the highaltitude throttles and having an extension passing loosely through ahole in the head of said'lever7 a collar on the control rod serving asa. stop for the lever, a fixed spring plate at the extremity of thecontrol rod,a loose spring plate between the said xed spring plate andthe lever head and a compression spring between the two spring plates.

In testimony whereof I affix my signature in presence of two witnesses.

MAX FRIZ lVitnesses z BRUNO KATZ, EMIL FRIZ.

